1. Field
The present disclosure relates generally to an organic light emitting diode (OLED) display.
2. Description of the Related Technology
An organic light emitting diode (OLED) display is a self emissive display device that displays images with organic light emitting diodes. Unlike the liquid crystal display (LCD), the organic light emitting diode (OLED) display does not require a separate light source, thereby making it possible to be implemented as a slim and lightweight display. Furthermore, as the organic light emitting diode display has high quality characteristics such as lower power consumption, high luminance, and short response time, it has been spotlighted as a next generation display device.
Organic light emitting diode displays are classified as passive matrix and active matrix types depending upon the driving method. With the active matrix type of organic light emitting diode display, an organic light emitting diode, a thin film transistor (TFT), and a capacitor are formed for each of the pixels so as to control each pixel in an independent manner.
The capacitor may be formed simultaneously with the thin film transistor. For example, both electrodes of the capacitor may be formed simultaneously with a semiconductor layer and a gate electrode of the thin film transistor, respectively. In this instance, the semiconductor layer and one of the two electrodes of the capacitor include an impurity-doped polycrystalline silicon layer.
Meanwhile, in order to form one of the capacitor electrodes with an impurity-doped silicon layer, it is required to provide a separate doping masking process for forming the electrode, and this involves complicated processing steps and increased production cost.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.